CVE-2026-4648

Insufficient Encryption Level in CasfID Servicios Tecnológicos NFC Wristbands

Published Jul 28, 2026 CVSS 4.0 · 6.8 Medium EPSS < 1% KEV · Not listed
Description
Use of an insecure cryptographic algorithm in the cashless payment system using NFC wristbands from CasfID Servicios Tecnológicos S.L.U. (version used at Resurrection Fest 2025), which employs cards based on MIFARE Classic technology (FM11RF08S). The cryptographic weakness of the authentication algorithm allows an attacker to retrieve access keys using techniques known as Backdoored Nested Attack, read the wristband’s entire contents, and clone its credentials onto a compatible rewritable card. Exploitation of this vulnerability could enable the impersonation of other attendees, the fraudulent use of the balance associated with their wristbands, and financial losses for both the affected users and the event organizers.

Remediation

Vendor Solution

Since the vulnerability stems from a hardware-level cryptographic weakness inherent in the MIFARE Classic family, it is recommended to discontinue the use of these chips (such as the FM11RF08S variant) for payment systems and critical access control systems. As a definitive solution, organizations should migrate to smart card technologies that support robust, up-to-date cryptographic standards (such as AES-128 or higher), such as the MIFARE DESFire family (EV2 or EV3).

Tracking

Sign in to view the affected projects.

Advisories

No advisories available
History
Type Values Removed Values Added
First Time appeared Casfid Servicios Tecnológicos
Casfid Servicios Tecnológicos nfc Wristbands
Vendors & Products Casfid Servicios Tecnológicos
Casfid Servicios Tecnológicos nfc Wristbands
Type Values Removed Values Added
Description Use of an insecure cryptographic algorithm in the cashless payment system using NFC wristbands from CasfID Servicios Tecnológicos S.L.U. (version used at Resurrection Fest 2025), which employs cards based on MIFARE Classic technology (FM11RF08S). The cryptographic weakness of the authentication algorithm allows an attacker to retrieve access keys using techniques known as Backdoored Nested Attack, read the wristband’s entire contents, and clone its credentials onto a compatible rewritable card. Exploitation of this vulnerability could enable the impersonation of other attendees, the fraudulent use of the balance associated with their wristbands, and financial losses for both the affected users and the event organizers.
Title Insufficient Encryption Level in CasfID Servicios Tecnológicos NFC Wristbands
Weaknesses CWE-326
References
Metrics cvssV4_0

{'score': 6.8, 'vector': 'CVSS:4.0/AV:P/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N'}

ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
INCIBE
Published
Updated
Jul 28, 2026, 12:04 PM
Reserved
Mar 23, 2026, 12:50 PM
Status
Deferred
Published
Jul 28, 2026, 12:16 PM
Modified
Oct 24, 2026, 1:10 PM